// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_FORMATS_MP2T_DESCRIPTORS_H_
#define MEDIA_FORMATS_MP2T_DESCRIPTORS_H_

#include <stdint.h>

#include <map>
#include <string>

namespace media {

class BitReader;

namespace mp2t {

    // Representation of a list of descriptors, used in the MPEG-2 Systems standard
    // to extend the definitions of programs or program elements. While the standard
    // appears to permit multiple descriptors in such a list to have the same tag
    // value, the implementation herein will not support this.
    class Descriptors {
    public:
        Descriptors();
        Descriptors(const Descriptors& other);
        ~Descriptors();

        // Attempts to read a (possibly empty) list of descriptors from the |reader|.
        // If |size| > 0, the descriptors must occupy exactly |size| bytes, Otherwise,
        // the descriptors should use all available bits from the reader.
        bool Read(BitReader* reader, int size);

        // Indicates whether a Registration descriptor is present. If so, the
        // |format_identifier| and |additional_info| values are populated with the
        // contents of the descriptor.
        bool HasRegistrationDescriptor(int64_t* format_identifier,
            std::string* additional_info) const;

        // Indicates whether a CA descriptor is present. If so, the |system_id|,
        // |pid|, and |private_data| values are populated with the contents of the
        // descriptor.
        bool HasCADescriptor(int* system_id,
            int* pid,
            std::string* private_data) const;

        // Indicates whether a CA descriptor is present, and if so, whether it is
        // of the type defined by ISO/IEC 23001-9:2014 (i.e. with a specific
        // system_id value and layout of the private_data). If so, the |ca_pid| and
        // |pssh_pid| are populated with the contents of the descriptor.
        bool HasCADescriptorCenc(int* ca_pid, int* pssh_pid) const;

        // Indicates whether a Private Data Indicator descriptor is present with a
        // particular |value|.
        bool HasPrivateDataIndicator(int64_t value) const;

    private:
        using Descriptor = std::pair<int, std::string>;
        std::map<int, std::string> descriptors_;

        // Allow copy and assign so that it can be used in a std C++ container.
    };

} // namespace mp2t
} // namespace media

#endif // MEDIA_FORMATS_MP2T_DESCRIPTOR_LIST_H_
